Fig 1: FH knockdown upregulates AMPK phosphorylation and downregulates DAB2 expression. (A) DAB2 was downregulated in FH knockdown cells, as identified by using the human signal transduction pathway finder RT2 profiler PCR array. (B) Bar graphs showing the fold change in IFRD1, JAG1 and DAB2 mRNA levels compared with the shluc control group based on the RT2 profiler PCR array results. Western blots showing FH, DAB2, p-AMPK, and AMPK protein expression in (C) FH knockdown CL1-0 and H441 cells and FH overexpressing H1299 cells and (D) H441 cells treated with 15 µM BML75 (in 1% FBS containing medium, 24 h). (E) Schematic diagram of the FH signaling pathway in lung cancer cells. All western blots were performed twice independently. FH, fumarate hydratase; shFH, short hairpin RNA targeting FH; shluc, shRNA targeting firefly luciferase; DAB2, disabled homolog 2; IFRD1, interferon-related developmental regulator 1; JAG1, jagged canonical Notch ligand 1; p-, phosphorylated; TCA, tricarboxylic acid cycle.